added name2cas+cas2smiles lookup in case name2smiles fails

ChemID.py

@@ -83,9 +83,13 @@ def ResolveChemical(chemName, IDtype):
 
         name, name_origin = name2iupac(name)
         smiles = name2smiles(name)
+        if not smiles:
+            cas = name2cas(name)
+            smiles = cas2smiles(cas)
 
         if smiles:
-            cas = name2cas(name)
+            if not cas:
+                cas = name2cas(name)
             try:
                 mol = Chem.MolFromSmiles(smiles)
             except: